How to Remove Mould from Walls and Ceilings

Removing mould from walls and ceilings is not just about appearance. Those dark patches usually point to excess moisture, poor ventilation or water ingress, and they can also worsen allergies and breathing problems. For that reason, professional decorators typically tackle the job on two fronts: they clean away the visible fungus and put measures in place so it does not come back quickly, using straightforward products, improving airflow and, where needed, repainting correctly.

How to identify the source of mould on walls?

Before any cleaning starts, professionals work out where the moisture is coming from, because that determines whether a thorough clean is enough or whether a structural fix is required. Warning signs such as blown plaster, paint peeling off in sheets, or stains that spread quickly can indicate a leak and may call for a plumber or a damp-proofing/waterproofing specialist.

If the moisture is only on the surface-often linked to limited air circulation or steam from showers and cooking-the problem can usually be handled with careful cleaning and small touch-ups. Even so, it is wise to keep an eye on the area for a few days to confirm the issue is genuinely under control.

Watch a video on the Clube do Pintor YouTube channel about effective homemade mixes for cleaning damp stains and helping to stop mould from returning:

https://www.youtube.com/watch?v=qMiwKIn0N7w

How to clean mould from walls step by step?

The most common approach for removing mould is a 1:1 mix of water and household bleach, applied straight onto the affected areas with a sponge, cloth or spray bottle-always with the windows open. Some decorators add a small amount of mild washing-up liquid to help lift greasy residue and built-up dirt, leaving it to work for a few minutes before gently scrubbing.

Another popular option-especially in small bedrooms or for anyone who is sensitive to the smell of chlorine-is neat white distilled vinegar. Apply it to the mould, leave it for 20 to 30 minutes, then wipe clean with a dry cloth. In larger areas or where mould is well established, dedicated anti-mould products can be used to support the initial clean.

How to prepare a mouldy wall for a fresh coat of paint?

Once the visible mould has been removed, the area needs to dry out fully-anything from a few hours to a full day-so you are not painting over lingering damp. When the surface is dry, many decorators lightly sand with a fine-grade abrasive to smooth it and remove loose residue, then fill small holes with filler before sanding again gently.

After that, it is usually best to apply an acrylic sealer or stabilising primer, which improves paint adhesion and helps to block minor residual moisture. For the top coat, washable acrylic paints or those labelled as mould-resistant are commonly chosen. In kitchens, bathrooms and utility areas, paints formulated for damp environments tend to cope better with steam and condensation.

What care helps to prevent mould from coming back?

Getting rid of mould is only part of the fix: everyday habits reduce trapped moisture and keep air moving, making it harder for staining to reappear. In colder or wetter climates, a quick visual check each time the season changes can help you spot early signs of mould, which are far easier to deal with.

A few simple measures recommended by decorators and home-maintenance specialists can be followed routinely:

• Open doors and windows for a few minutes each day to refresh the air.
• Avoid drying clothes in bedrooms or living rooms; use outdoor lines or well-ventilated spaces instead.
• Use extractor fans, fans or dehumidifiers in rooms that are naturally damp.
• Check gutters, roofs and pipework from time to time to catch leaks early.
• Pull large furniture a few centimetres away from the wall to reduce condensation.

If small patches appear, cleaning them promptly with the methods above and improving ventilation typically prevents major remedial work; the space stays visibly cleaner, smells fresher and carries a lower risk associated with fungal growth indoors.